code: def temp_filename(ext: str) -> str:
      """Generate a temporary, writable filename with the given extension"""
      # todo: not safe - the file is deleted before being written to so another
      # process can generate the same filename
      with NamedTemporaryFile(suffix="." + ext) as f:
          return f.name
  
file_path: bokeh/src/bokeh/io/util.py
imports: from __future__ import annotations
  import logging
  import os
  import sys
  from os.path import basename, dirname, join, splitext
  from tempfile import NamedTemporaryFile
label_desc: Use image node_id 3 for calling a global function with example usage: temp_filename(ext) and returns: f